From 7c47f5afdeef763599f1ae22d29b8c3904c58315 Mon Sep 17 00:00:00 2001 From: Julian Wiedmann Date: Fri, 23 Aug 2019 11:48:47 +0200 Subject: s390/qdio: enable drivers to poll for Output completions While commit d36deae75011 ("qdio: extend API to allow polling") enhanced the qdio layer so that drivers can poll their Input Queues, we don't have the corresponding infrastructure for Output Queues yet. Factor out a helper that scans a single QDIO Queue, so that qeth can implement TX NAPI on top of it. While doing so, remove the duplicated tracking of the next-to-scan index (q->first_to_check vs q->first_to_kick) in this code path. qdio_handle_aobs() needs to move slightly upwards in the code hierarchy, so that it's still called from the polling path. Signed-off-by: Julian Wiedmann Acked-by: Vasily Gorbik Signed-off-by: David S. Miller --- drivers/s390/cio/qdio_main.c | 64 +++++++++++++++++++++++++++++--------------- 1 file changed, 43 insertions(+), 21 deletions(-) (limited to 'drivers/s390/cio') diff --git a/drivers/s390/cio/qdio_main.c b/drivers/s390/cio/qdio_main.c index 4142c85e77d8..5efba0d29190 100644 --- a/drivers/s390/cio/qdio_main.c +++ b/drivers/s390/cio/qdio_main.c @@ -647,8 +647,6 @@ static void qdio_kick_handler(struct qdio_q *q, unsigned int count) qperf_inc(q, outbound_handler); DBF_DEV_EVENT(DBF_INFO, q->irq_ptr, "koh: s:%02x c:%02x", start, count); - if (q->u.out.use_cq) - qdio_handle_aobs(q, start, count); } q->handler(q->irq_ptr->cdev, q->qdio_error, q->nr, start, count, @@ -774,8 +772,11 @@ static inline int qdio_outbound_q_moved(struct qdio_q *q, unsigned int start) count = get_outbound_buffer_frontier(q, start); - if (count) + if (count) { DBF_DEV_EVENT(DBF_INFO, q->irq_ptr, "out moved:%1d", q->nr); + if (q->u.out.use_cq) + qdio_handle_aobs(q, start, count); + } return count; } @@ -1655,6 +1656,44 @@ rescan: } EXPORT_SYMBOL(qdio_start_irq); +static int __qdio_inspect_queue(struct qdio_q *q, unsigned int *bufnr, + unsigned int *error) +{ + unsigned int start = q->first_to_check; + int count; + + count = q->is_input_q ? qdio_inbound_q_moved(q, start) : + qdio_outbound_q_moved(q, start); + if (count == 0) + return 0; + + *bufnr = start; + *error = q->qdio_error; + + /* for the next time */ + q->first_to_check = add_buf(start, count); + q->qdio_error = 0; + + return count; +} + +int qdio_inspect_queue(struct ccw_device *cdev, unsigned int nr, bool is_input, + unsigned int *bufnr, unsigned int *error) +{ + struct qdio_irq *irq_ptr = cdev->private->qdio_data; + struct qdio_q *q; + + if (!irq_ptr) + return -ENODEV; + q = is_input ? irq_ptr->input_qs[nr] : irq_ptr->output_qs[nr]; + + if (need_siga_sync(q)) + qdio_siga_sync_q(q); + + return __qdio_inspect_queue(q, bufnr, error); +} +EXPORT_SYMBOL_GPL(qdio_inspect_queue); + /** * qdio_get_next_buffers - process input buffers * @cdev: associated ccw_device for the qdio subchannel @@ -1672,13 +1711,10 @@ int qdio_get_next_buffers(struct ccw_device *cdev, int nr, int *bufnr, { struct qdio_q *q; struct qdio_irq *irq_ptr = cdev->private->qdio_data; - unsigned int start; - int count; if (!irq_ptr) return -ENODEV; q = irq_ptr->input_qs[nr]; - start = q->first_to_check; /* * Cannot rely on automatic sync after interrupt since queues may @@ -1689,25 +1725,11 @@ int qdio_get_next_buffers(struct ccw_device *cdev, int nr, int *bufnr, qdio_check_outbound_pci_queues(irq_ptr); - count = qdio_inbound_q_moved(q, start); - if (count == 0) - return 0; - - start = add_buf(start, count); - q->first_to_check = start; - /* Note: upper-layer MUST stop processing immediately here ... */ if (unlikely(q->irq_ptr->state != QDIO_IRQ_STATE_ACTIVE)) return -EIO; - *bufnr = q->first_to_kick; - *error = q->qdio_error; - - /* for the next time */ - q->first_to_kick = add_buf(q->first_to_kick, count); - q->qdio_error = 0; - - return count; + return __qdio_inspect_queue(q, bufnr, error); } EXPORT_SYMBOL(qdio_get_next_buffers); -- cgit v1.2.3-59-g8ed1b From 313dc689b16c08b081939ee9b87dac3736c780e3 Mon Sep 17 00:00:00 2001 From: Julian Wiedmann Date: Fri, 23 Aug 2019 11:48:48 +0200 Subject: s390/qdio: let drivers opt-out from Output Queue scanning If a driver wants to use the new Output Queue poll code, then the qdio layer must disable its internal Queue scanning. Let the driver select this mode by passing a special scan_threshold of 0. As the scan_threshold is the same for all Output Queues, also move it into the main qdio_irq struct. This allows for fast opt-out checking, a driver is expected to operate either _all_ or none of its Output Queues in polling mode. Signed-off-by: Julian Wiedmann Acked-by: Vasily Gorbik Signed-off-by: David S. Miller --- arch/s390/include/asm/qdio.h | 2 +- drivers/s390/cio/qdio.h | 3 +-- drivers/s390/cio/qdio_main.c | 11 ++++++++--- drivers/s390/cio/qdio_setup.c | 2 +- 4 files changed, 11 insertions(+), 7 deletions(-) (limited to 'drivers/s390/cio') diff --git a/arch/s390/include/asm/qdio.h b/arch/s390/include/asm/qdio.h index 79b4a3e9dc5d..556d3e703fae 100644 --- a/arch/s390/include/asm/qdio.h +++ b/arch/s390/include/asm/qdio.h @@ -359,7 +359,7 @@ struct qdio_initialize { qdio_handler_t *output_handler; void (**queue_start_poll_array) (struct ccw_device *, int, unsigned long); - int scan_threshold; + unsigned int scan_threshold; unsigned long int_parm; struct qdio_buffer **input_sbal_addr_array; struct qdio_buffer **output_sbal_addr_array; diff --git a/drivers/s390/cio/qdio.h b/drivers/s390/cio/qdio.h index a06944399865..a58b45df95d7 100644 --- a/drivers/s390/cio/qdio.h +++ b/drivers/s390/cio/qdio.h @@ -206,8 +206,6 @@ struct qdio_output_q { struct qdio_outbuf_state *sbal_state; /* timer to check for more outbound work */ struct timer_list timer; - /* used SBALs before tasklet schedule */ - int scan_threshold; }; /* @@ -295,6 +293,7 @@ struct qdio_irq { struct qdio_ssqd_desc ssqd_desc; void (*orig_handler) (struct ccw_device *, unsigned long, struct irb *); + unsigned int scan_threshold; /* used SBALs before tasklet schedule */ int perf_stat_enabled; struct qdr *qdr; diff --git a/drivers/s390/cio/qdio_main.c b/drivers/s390/cio/qdio_main.c index 5efba0d29190..5b63c505a2f7 100644 --- a/drivers/s390/cio/qdio_main.c +++ b/drivers/s390/cio/qdio_main.c @@ -880,7 +880,7 @@ static inline void qdio_check_outbound_pci_queues(struct qdio_irq *irq) struct qdio_q *out; int i; - if (!pci_out_supported(irq)) + if (!pci_out_supported(irq) || !irq->scan_threshold) return; for_each_output_queue(irq, out, i) @@ -973,7 +973,7 @@ static void qdio_int_handler_pci(struct qdio_irq *irq_ptr) } } - if (!pci_out_supported(irq_ptr)) + if (!pci_out_supported(irq_ptr) || !irq_ptr->scan_threshold) return; for_each_output_queue(irq_ptr, q, i) { @@ -1528,6 +1528,7 @@ set: static int handle_outbound(struct qdio_q *q, unsigned int callflags, int bufnr, int count) { + const unsigned int scan_threshold = q->irq_ptr->scan_threshold; unsigned char state = 0; int used, rc = 0; @@ -1566,8 +1567,12 @@ static int handle_outbound(struct qdio_q *q, unsigned int callflags, rc = qdio_kick_outbound_q(q, 0); } + /* Let drivers implement their own completion scanning: */ + if (!scan_threshold) + return rc; + /* in case of SIGA errors we must process the error immediately */ - if (used >= q->u.out.scan_threshold || rc) + if (used >= scan_threshold || rc) qdio_tasklet_schedule(q); else /* free the SBALs in case of no further traffic */ diff --git a/drivers/s390/cio/qdio_setup.c b/drivers/s390/cio/qdio_setup.c index d4101cecdc8d..f4ca1d29d61b 100644 --- a/drivers/s390/cio/qdio_setup.c +++ b/drivers/s390/cio/qdio_setup.c @@ -248,7 +248,6 @@ static void setup_queues(struct qdio_irq *irq_ptr, output_sbal_state_array += QDIO_MAX_BUFFERS_PER_Q; q->is_input_q = 0; - q->u.out.scan_threshold = qdio_init->scan_threshold; setup_storage_lists(q, irq_ptr, output_sbal_array, i); output_sbal_array += QDIO_MAX_BUFFERS_PER_Q; @@ -474,6 +473,7 @@ int qdio_setup_irq(struct qdio_initialize *init_data) irq_ptr->nr_input_qs = init_data->no_input_qs; irq_ptr->nr_output_qs = init_data->no_output_qs; irq_ptr->cdev = init_data->cdev; + irq_ptr->scan_threshold = init_data->scan_threshold; ccw_device_get_schid(irq_ptr->cdev, &irq_ptr->schid); setup_queues(irq_ptr, init_data); -- cgit v1.2.3-59-g8ed1b